Rubber heel



.My 23, 19290 E. lKROEGER RUBBER HEEL Filed Sept. 9, 1926 INVENTOR. Ea nW JE/m firvozam A TTORNE.

Patented July 23, 1929.

UNITED STATES PATENT OFFICE.

EDWIN JOHN KROEGEB, 0F AKRON. OHIO, ASSIGNOB TO JOHN B. GAMMETER, OF

AKRON, OHIO.

RUBBER HEEL.

Application flled September 9, 1926. Serial No. 134.350.

This invention relates to rubber heels and methods for producing thesame.

The general purpose of the invent-ion'is to provide a rubber heelconstruction with an insert through which nails can be driven any whereand which will effectively prevent the heel from working off the nails,thus obviating forming heels with nail holes and using metalreenforcements, such as washers or the like, about the nail holes.

Particularly, one object of the invention is to provide a light,inexpensive, highly resilient rubber heel of absolutely waterproofconstruction, including an insert of hard cellular rubber, such asvulcanized, hard sponge rubber, which may be vulcanized in the heelwithout special treatment to produce an integral heel construction, thecellular structure of the insert being such that a nail penetratingcertairicells will not collapse the walls of adjacent cells, so that theinsert will not'split or crack.

Another object of the invention is to provide a rubber heel with anail-receiving insert therein, both mechanically and chemically unitedwiththe body of the heel.

Another. object of the invention is to provide aheel capable of beingapplied to footwear by automatic nailing machines.

Another object of the invention is to provide as an article ofmanufacture a rubber heel in which the nails have been started so thatthe cobbler need only apply the heel to the foot-wear and drive in thenails, handling of the nails thus being avoided;

Another object of the invention is to provide a method for producing theabove heel. This method preferably comprises vulcanizingthe heel withthe insert, said insert being either previously completely or partiallyvulcanized oi' compounded of rubber capable of vulcanizing duringvulcanization of the heel, the heel being vulcanized under such pressureas to prevent distortion of the heel by expansion of the gases in thecellular insert.

The foregoing and other objects of the invention are obtained by theheel construction illustrated in the. accompanying drawings anddescribed below. It is to be understood that the invention is notlimited to the specific form thereof shown and described.

(ll the accompanying drawings:

Figure l is a bottom plan of a heel embodying the invention;

- Figure 2 is a top plan thereof;

Figure I is a section on line 3-3 of Figure 1;

Figure 4 is a section on line 4-4 of Figure 2; and

Figure 5 is a perspective view of the heel illustrated with the nailsstarted, in which form the heels may be supplied by manufacturers.

Referring to the drawings, the numeral 10 designates the body portion ofthe heel which is of soft, tough rubber of the usual compositions suchas heretofore have been employed.

During the process of vulcanization of the heel 10 an insert 11,preferably of an outline similar to that of the heel, is embedded in thetop thereof, this insert preferably being formed of such material asvulcanized, hard sponge rubber either previously partly or whollyvulcanized or compounded rubber capable of vulcanizing hard duringvulcanization of the heel. obtained from sheets of vulcanized, hardsponge rubber of the required thickness as by punching the sametherefrom.v

The heel preferably is formed with a tread designed to define an area orareas in which nails may be driven, spaced ribs 12, 12 of the samegeneral shape as the outline of the heel being shown formed on thebottom thereof. the outer rib substantially coinciding with the outlineof the insert.

The heel 10 is made by mounting a blank of soft rubber with the insertthereon infa mold adapted to exert pressure thereon during vulcanizationsuchthat the soft rubber will How about the edges of the insert asillustrated at 13 to anchor the insert in the heel. The soft rubber alsofurther interlocks mechanicallywith'the insert by flowing into thebroken cells in the edges thereof.

' ltn addition to the mechanicalconnection between the body of the heeland the insert, the two also become chemically united during thevulcanizing process as will be understood by skilled artisans.

The pressure employed during vulcanization is such as to preventexpansion of the gases within the cells of the sponge rubber The inserts11 may be from distorting the heel. As a further advantage, the pressureof the gas will conipensate for the expansion of the rubber dur mgvulcanization, so that no rind or overflow will occur, thus eliminatingthe usual trimming operations.

After the heels have been vulcanized, they may be shipped to factoriesfor use on new footwear, the construction thereof per1nit ting theireffective application with automatic nailing machines, there being nospecially located holes which the nails must lind. \Vhen shipped tocobblers or for retail trade, the heels preferably are shipped with thenails started as shown in Figure 5.

it is to be noted that no special treatment of the hard sponge orcellular rubber is required so that. it may be elfectively bonded to thesoft rubber of the heel, that it is both mechanically and chemicallyunited to the body of the heel and that in use it will not split orcrack. The heel also permits of easy removal and replacement by personswho desire to change their rubber heels about because of uneven Wear.

Llodifieations of the invention may be resorted to without departingfrom the spirit thereof or the scope of the appended claims.

\Vhat' is claimed is:

1. A soft rubber heel having a nail-receiving insert secured thereinduring vul- -anization thereofisaid insert being of vul- 'anized hardsponge rubber.

2. A soft rubber heel having a nail-receiv inginsert secured therein,said insert being of vulcanized hard sponge rubber.

A soft rubber heel having a nail-receiving insertof cellular hard rubbersecured therein.

EDWIN JOHN KROEGER.

